I will assume you're inbound as an ENJJPT student. On base is great for the commute, the community, and the VERY NICE houses. If you are forced to live off base, it all depends on your priorities.
If you value the short commute and want a fairly nice house, Expressway Village is a subdivision right outside the gate (Missile Rd) that's closest to ENJJPT. You can find a nice house in that neighborhood for around $1200 per month (lease).
If you want to live out in the country on a large piece of land with a 15 minute commute, Iowa Park and Burkburnett are nice places.
If you want a really nice house, there are a few nice neighborhoods. Look at Tanglewood (North of Seymore Hwy), around Midwestern University, and down by the new Walmart on SW Pkwy.
Places to avoid are City View, anywhere inside the triangle formed by 44, Kell, and Seymore, and the area just outside Sheppard's main gate south of housing.